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Tatsuro Matsui, Masahiro Yamada, Shinichiro Katayama, Hiroshi Morimoto
1996 Volume 22 Issue 2 Pages
227-233
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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It is impossible to separate styrene from a C 8 distillate in an ethylene plant by conventional distillation because the difference of boiling point between styrene and o-xylene is only 0.8°C. If dimethyl acetoamide is adopted as an extractive agent, the relative volatility of styrene and o-xylene becomes higher, and we can industrially separate styrene from C 8 distillate. From vapor liquid equilibrium data of dimethyl acetoamide, styrene, o-xylene and m-xylene, Wilson parameters were determined and several methods of distillation calculation with four components computer programming were made. The improved Amundson method was most beneficial for the case study of distillation calculation. With computer programming, design parameters such as theoretical plate number, feed plate, reflux ratio and solvent ratio were studied. We also experimented with extractive distillation with a 100 plate, Oldershaw type distillation tower and compared the data with calculated results. Experimental results were consistent with calculated results if we adjusted the efficiency of the distillation tower and its internal reflux.
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Noriyuki KOBAYASHI, Hiroki KATAYAMA, Kazunari FUSHITANI, Norio ARAI, Y ...
1996 Volume 22 Issue 2 Pages
234-240
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The fundamental characteristics of degradation of carbon fiber-reinforced/carbon composite materials (C/C composites) in reducing and high-temperature gas streams were experimentally studied. Test samples of C/C composite and reference samples of graphite were exposed to a reducing atmosphere generated by a fuel-rich premixed combustion of methane-air in which little oxygen was believed to exist for 30 minutes.The weight loss fractions of the samples were measured under the equivalence ratios of 0.93, 1.3 and 1.4. After cooling the samples, the features of the surface were observed by a scanning electron microscope.
The results of the experimental observation revealed that the C/C composite lost weight more readily than the graphite under the same experimental conditions. The degradation of the matrix of the C/C composite took place prior to that of the carbon fibers, and the chemical degradation became more remarkable by raising of the temperature. The fabric of the carbon fibers additionally peeled off beyond about 1330 K thus increasing the weight loss fractions in a step-wise manners. Moreover, the degradation was restrained by the coexistence of carbon monoxide or hydrogen, and the effect was promoted with increasing equivalence ratio of methane-air. The reason may be that the equilibrium of the reaction ; C+ H
2O = CO + H
2 was shifted to the left side.
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Tadaaki Tanii, Masaki Minemoto, Kuniyasu Nakazawa, Yoshimasa Ando
1996 Volume 22 Issue 2 Pages
241-248
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Experiments were performed to investigate the possibility of a direct-contact-charged cool storage system and indirect-contact-charged cool storage system using clathrate for use in air conditioning of buildings, by storing energy of night excess power at a cool storage density and taking it out as cool heat when energy become necessary in the daytime. Using CFC-11 (CCl
3F) clathrate, the following conclusions were obtained.
1. Cool storage system using clathrate is a more suitable heat storage system than water and ice.
2. Addition of 0.010.1 wt% additive allowed ideal clathrate formation and decomposition up to 40 wt% of clathrate concentration.
3. Addition of ethyleneglycol allowed clathrate formation and decomposition temperature decreases, resulting in the aquisition of more cooled chilled water.
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Noboru Kamei, Setsuro Hiraoka, Yoshihito Kato, Yutaka Tada, Katsuki Iw ...
1996 Volume 22 Issue 2 Pages
249-256
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Power Consumption under turbulent flow in a baffled agitated vessel with paddle impeller was measured for different impeller dimensions. The power number at the standard baffle condition was then correlated well with a parameter
np0.7 (
b/d), where
b, d and
np are impeller blade width, impeller diameter and the number of impeller blades, respectively. The power correlation under fully baffled conditions was derived using the parameter
np0.7 (
b/d). On the other hand, from a model analysis of the drag force acting on a baffle plate, the power number under weakly baffled conditions was correlated well with the parameter (
Bw/ D)
nb0.8, where
Bw, D and
nb are baffle plate width, vessel diameter and the number of baffle plates, respectively. The resultant correlation was expressed as
Np-Npo=4.5 (
BW/D)
nb0.8Npmax0.8where
Npo and
Npmax were power number under non-baffled conditions and that under fully baffled conditions, respectively. From the derivation of the power correlation over wide range of baffle and impeller dimensions, the fully baffled condition was expressed by the following equation
(
BW/D)
nb0.8=0.27
Npmax0.2
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Michito Kanamori, Hitoki Matsuda, Masanobu Hasatani
1996 Volume 22 Issue 2 Pages
257-263
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The applicability of the Ca (OH)
2/ CaO thermochemical reaction for storing nighttime heat derived from electricity was studied. The heat releasing rate, heat output, and thermal efficiency were investigated experimentally by the use of a lab-scaled heat storage unit incorporated with a fin-type heat exchanger.
It was found that when water vapor at ambient temparature of around 300 K was introduced to the reactor, the temperature of the CaO reactant bed during the heat-releasing step was increased to around equiliburium temperature at 610 K. The hydration heat produced was then recovered by the heat exchanger medium (city water) the temperature of which was rapidly increased up to above 343 K. The amount of the heat recovered from the CaO packed bed was about four times higher than that which might be recovered if the energy storage was carried out by the sensible heat of water in the same volume.
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Yoshio Fuchigami, Masaya Nagai, Tsuyoshi Sugiyama
1996 Volume 22 Issue 2 Pages
264-269
Published: March 10, 1996
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In the previous paper we proposed a “mixing factor, α” which was obtained from the actual radical polymerization in a CSTR reactor using very short-life initiator with a life typically of the order of 230 s.The optimization of the reaction condition for the continuous bulk polymerization of methyl methacrylate was studied with a bench scale reactor (diameter, D =155 mm) using a WHR impeller, where the impeller Reynolds number, Re < 50 (laminar flow). In the present paper, the mixing ability of the Maxblend ® (MB) impeller was evaluated by using a α value 45 times that of the double herical ribbon (WHR) impeller at the pilot scale reactor (D=500 mm), where Re > 50 (transition and turburent flow). The optimum conditions of the bench scale reactor were perfectly matched in at the commercial reactor (D=1700 mm) by using the MB impeller, where Re >100. A scale-up factor was proposed for the MB impeller having a different ratio of the liquid level to the reactor diameter.
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Hidehiko Noda, Jun Shiraishi, Yoshihide Nagafuchi, Osamu Miyatake
1996 Volume 22 Issue 2 Pages
270-276
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The maximum capillary pressure of a screen is one of a the most important factors to predict the maximum heat transfer rate of a heat pipe in which a screen wick is installed. An analytical study on the maximum capillary pressure of a plain screen is conducted by taking into account the screen geometry and the effects of adjusting menisci upon the rupture of the meniscus on the assumption that it is circular. The maximum capillary pressure is also investigated experimentally to define the effect of the contact angle on the shape of the meniscus. From a correlation between the analytical and experimental results, a semi-empirical equation for predicting the maximum capillary pressure of the plain screen wicks is obtained.
The equation shows that the maximum capillary pressure decreases with the increase of the contact angle, and even if the contact angle is greater than π/2 rad, the screen wicks can sustain a large liquid pumping head.
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Tetsu Kitsukawa, Masaru Ishida, Hiroyuki Hatano
1996 Volume 22 Issue 2 Pages
277-286
Published: March 10, 1996
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A monolayer-particle fluidized bed is constructed to elucidate the behavior of particles. By using a high-speed video camera, observation and recording of the movement of particles, especially around bubbles were performed. The pictures were saved as data files in a personal computer by applying an image analyzer.
Data files consist of 470 × 370 pixels having 256 grades of brightness for each pixel. Then a program that recognizes each individual particle and searches for its loci from the consequential data files is made by tracing pixels with brightness higher than a certain threshold value. Also, a program for calculating the velocity of each particle is developed. In this program, each picture is divided into 100 blocks and a typical velocity of the particles in the block is calculated by comparing it with that in the next picture. By this typical velocity of the block, each particle can find the position in the next picture. In this manner, the velocity of each particle can be calculated.
The characteristic feature of this system is to be able to trace all the particles continuously without any tracer particle. The applicability of this system to trace the complex behavior of particles around a bubble confirms its effectiveness.
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Hironori Kitazaki, Masayuki Ishimaru, Katsutoshi Inoue, Kumiko Yoshida
1996 Volume 22 Issue 2 Pages
287-293
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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In this work, solvent extraction behaviors of some commercial extractants such as tri-n-octylphosphine oxide (TOPO), Cyanex 923 and Cyanex 925 for baicalein and baicalin decocted from Suctellaria root, which is a crude drug, were examined to elucidate their mutual separation by solvent extraction. Baicalein was extracted selectively by trialkylphosphine oxides over baicalin. From analyses of the extraction mechanism, the equilibrium constant of extraction reaction and enthalpy change were evaluated. A porous resin impregnated with Cyanex 923 in XAD-7 was prepared to remove baicalein from baicalin by using a column packed with the resin. Baicalein was able to be completely removed by this column operation.
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Kenji Kawasaki, Akira Matsuda, Toshiro Murase
1996 Volume 22 Issue 2 Pages
294-300
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Activated sludge has bound water which adheres tightly to the surface and in the inside of suspended solid (microorganisms). To study the effect of the bound water on the filtration and consolidation characteristics, the wet basis average specific filtration resistance α
av.w (base solid contains the bound water) and the wet basis modified consolidation coefficient
Ce.w are rationally derived and compared with the dry basis ones α
av.d,
Ce.d (base solid does not contain the bound water) which have been used conventionally. The wet and dry basis filtration and consolidation characteristics are measured using both the sewage excess activated sludge and that treated by the freezing and thawing treatment.
α
av, w is determined from the constant pressure filtering test by the analytical method proposed in this paper. The value of α
av.w is smaller than that of the dry basis one. The measured values of α
av.w for the excess activated sludge decrease to about one-fifty fifth by the freezing and thawing process and the improvement of the filtration characteristics is very large.
Ce.w is also determined from the constant pressure consolidation test by the analytical method proposed in this paper. The values of
Ce. w are larger than those of the dry basis one, and nearly constant in the applied pressure range (
p= 206 2950 kPa) of this experiment.
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Toshifusa Doi, Nobukazu Osaki, Kazuhito Nagayama, Shintaro Furusaki
1996 Volume 22 Issue 2 Pages
301-308
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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We investigated the transient characteristics of an oxygen electrode with a 50 μm PTFE membrane, which was employed to determine the liquid-phase volumetric oxygen transfer coefficient
kLa' in a bubble column with air-water and a 65 vol. % glycerol solution system. The transient response curve of the probe in this case was represented by the semi-empirical equations proposed in this work. These equations have three parameters, i.e.,
kLa', the response time lag τ and the inverse first-order time constant
k of the probe. These parameters were estimated by the nonlinear curve fitting of the experimental response data. The τ value was independent of superficial gas velocity and decreased with the rise in temperature of the liquid. The
k value increased with increasing superficial gas velocity. It was found that the first-order delay of the response curve depended on the
k/kLa' value and increased rapidly below
k/kLa'= 5. The
k/kLa' values of water and 65 vol.% glycerol solution were in the range of about 2 to 6. The
kLa' value determined from the slope of the strait line portion of the semi-logarithmic plot of the experimental response data was about 80 to 95% of that determined by the nonlinear curve fitting at
k/
kLa'= 2.
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The relationship between optimum clearance and film thickness
Masamichi Yoshida, Akira Ishita, Katsumasa Kinoshita, Hisashi Miyashit ...
1996 Volume 22 Issue 2 Pages
309-316
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Heat transfer enhancement in a rectangular duct with a semicylindrical turbulence promoter was experimentally studied for a high-Prandtl number fluid. The measurements of mass transfer coefficient and wall shear stress as well as flow visualization are performed in order to investigate how the performance of a promoter of heat transfer enhancement is influenced by its inclination angle and by the clearance between the promoter and the wall surface.
When the inclination angle is 0°, the variation of performance with clearance is closely related to the extent of heat transfer enhancement in the region of slipping flow. In this case, the clearance exhibiting the maximum performance is almost equal to the film thickness for a smoothed duct without a promoter. As the inclination angle increases, what influences the variation of performance with clearance gradually shifts to the extent of heat transfer enhancement in the region of circulating and reattaching flows, and the clearance exhibiting the maximum performance decreases.
There is no remarkable difference in the maximum performance between inclination angles examined here. It is, however, desirable to set the inclination angle to 30, since the distribution of the local mass transfer coefficient for this angle shows a less winding curve than those for other angles.
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Jianzhong Wang, Akiyoshi Sakoda, Motoyuki Suzuki
1996 Volume 22 Issue 2 Pages
317-325
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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When biological activated carbon (BAC) is applied to drinking water treatment, the mass transfer phenomena relatted to adsorption and biodegradation should be quantitatively clarified. As a method for evaluating adsorption and biodegradation in BAC separately, the moment analysis of pulse responses from BAC beds was proposed and the feasibility of such an approach was investigated. Theoretical moments of the pulse response from BAC and their simplified expressions useful in the case of drinking water treatment were derived for a model BAC employing activated carbon fiber (ACF). Adsorption capacities and microbial activities of various BACs were evaluated by the moment analysis when glucose and t-butyl alcohol were used as model organics. The chromatographic evaluation proposed and investigated in this work was found to be able to evaluate organic behavior in BAC applied for drinking water treatment.
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Kenichi Ushiki, Takashi Hibino, Teruyuki Sato, Mitsukuni Mizuno
1996 Volume 22 Issue 2 Pages
326-333
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The influence of initial agglomerate-size, gas velocity, and temperature on fluidizing behaviour and bed expansion of ultra-fine powders was examined by the use of a transparent set-up. The fluidizing behaviour was observed through transparent walls. Its behaviour was related to the change in primary agglom erate-size and the assumed secondary-one. The results showed that initial agglomerates were preservable to a certain degree during fluidization and that the size of the initial agglomerate considerably affected the fluidizing behaviour. Adsorbed water even binded strongly to the particle surface influencing secondary-agglomerate-size, and thus the amount of the adsorbed water significantly affected the fluidizing behaviour in the case of magnesia powder. Due to the formation of secondary agglomerates, incipient gas velocity increased at elevated temperature with decreasing initial agglomerate-size. It was found that a rise in gas velocity and bed expansion of up to 2 or 3 times cause almost no change in size of an assumed secondary agglomerate, at least in an uniform bed.
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Mitsuo Kamiwano, Meguru Kaminoyama, Kazuhiko Nishi
1996 Volume 22 Issue 2 Pages
334-341
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The authors have developed a new multi-point and fast-scanning system for measuring a concentration variation in a tube for continuous liquid flow, which is usually used as a tubular reactor or mixer. The system can continuously capture, as a pattern, the turbulent mixing state of a whole section of the tube using the electric conductivity method with electrode couples having high-frequency responsiveness. After ascertaining its performance and measuring precision, the authors investigated the enhancing effect of contain kinds of agitating objects, viz, a sphere, a disk, and a cylinder, on turbulent mixing in the tube. Object with various diameters were settled in a nozzle for subsidiary liquid flow of an aqueous electrolyte solution. It was found that a disk type object has the best effectiveness of the three kinds of objects, on condition that pressure loss resulting from the objects is identical among them.
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Hiroyuki Kage, Naoki Yada, Masae Kunimasa, Hironao Ogura, Yoshizo Mats ...
1996 Volume 22 Issue 2 Pages
342-349
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Microencapsulation of glass beads was carried out by complex coacervation of gelatin and acacia. Glass beads were chosen as the core material, because their surface was easily treated to be hydrophobic. We succeeded in excluding the complicated influence of emulsion on microencapsulation by the use of the coacervation method and a solid core material with narrow size distribution. The membrane of the microcapsule became thick with the increase of acetic acid dosage, while encapsulation was prevented by its excess addition because of the low pH value in the hardening process. Hydrophobizing of the core surface decreased the amount of acetic acid required to microencapsulate. A thin membrane was obtained due to the existence of salt, however the membrane thickness conversely became thick with a minute quantity of salt.
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Hideto Yoshida, Shinya Matsuura, Kouji Kanagawa, Ma Jiefu, Keiichi Nag ...
1996 Volume 22 Issue 2 Pages
350-355
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Experimental and theoretical studies have been conducted on a method for measuring particle concentration and size distribution in gas-solid pipe flow. The measurement can be done continuously and automatically by the use of anisokinetic sampling.
The total mass of the sampled particles, cyclone and filter box is measured by an electronic mass balance. The mass of the collected particles is proportional to the measurement time.
In the reduction of experimental data, mass median diameter and geometric standard deviation are determined uniquely by the use of Levin's Equation and the steepest descent mtehod.
Particle size distribution obtained in this way agrees well with the conventional impactor method.
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Wall Effects
Kunio Shinohara, Kunihito Takayasiki, Masaru Otani, Tomoyuki Uchiyama
1996 Volume 22 Issue 2 Pages
356-364
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Recently, there have been various studies on fabrication of composite particles to produce functional materials. Here, high-speed gas impact blending is utilized as a kind of surface-composite method to coat fine particles. The coating mechanism is investigated theoretically and experimentally. It is assumed that small particles move between the surfaces of large particles and the inner wall in collisions. The process is described by the number of small particles coated over the large ones after arbitrary impact times. The experimental results with binary sized particles agreed with simulated ones according to this theory. As a result, it was found that the transfer of small particles between large ones affects the distribution form of the number of small ones over large ones, and that the transfer between large particles and the inner wall governs the average number of small ones in addition. Therefore, it becomes possible to estimate the coating ratio of large particles in a certain processing time by this fabrication method.
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Hiroyuki Kage, Masae Kunimasa, Hideaki Kawahara, Hironao Ogura, Yoshiz ...
1996 Volume 22 Issue 2 Pages
365-371
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Microencapsulation of glass beads with a narrow size distribution was carried out by complex coacervation of gelatin and acacia. The coacervation process was observed in detail and the effects of agitation strength, cooling rate, addition time of core material, addition plans of acetic acid and distilled water, and heating rate in the hardening process on membrane thickness of the microcapsules were investigated systematically. The membrane thickness of the microcapsules increased under the operating conditions where low cooling rate and relatively strong agitation were utilized, and pH was changed moderately by discrete addition of acetic acid or distilled water over a certain time interval. It became clear that strict control of operating conditions at 19°C in the cooling process where the viscosity of the coacervate suddenly increases is remarkably important for the control of membrane thickness.
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Kenji Fukuchi, Katsumi Miyoshi, Yasuhiko Arai
1996 Volume 22 Issue 2 Pages
372-377
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The infinite dilution activity coefficients of alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol) in heavy paraffinic hydrocarbons (hexadecane and tetradecane) were measured in the region 20-80°C by a gas stripping method. The ASOG model was applied to calculate the infinite dilution activity coefficients. The infinite dilution activity coefficients can be correlated by adjusting the group interaction parameters between hydroxy and methyl groups.
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Hiromasa Komatsu, Hironobu Yamamoto
1996 Volume 22 Issue 2 Pages
378-384
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Vapor-liquid equilibrium data for two ternary systems of ethanol-water-dioxane and ethyl acetate-watwr-dioxane were observed by using an Othmer-type still at atmospheric pressure. Based on these data, Wilson parameters were determined. From correlation between the vapor-liquid equilibrium ratio and liquid compositions, the azeotropic composition of an ethanol (1) -water (2) -ethanol (3) system was estimated to be
x1=0.89,
x2=0.08 and
x3=0.03 in mole fraction. In addition, liquid-liquid equilibrium data of an ethyl acetate (1) -water (2) -dioxane (3) system were observed at 30°C and the plait point of this system was estimated to be
x1=0.15,
x2 = 0.61 and
x3= 0.24 in mole fraction.
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Katusyoshi Tanida, Yoshiyuki Sato, Hirokatsu Masuoka
1996 Volume 22 Issue 2 Pages
385-391
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The adsorption equilibrium loadings of supercritical carbon dioxide on BPL activated carbon were measured by an apparatus based on an isochoric method at temperatures of 313.2, 333.2 and 353.2 K and pressures up to 13 MPa. The pressure dependence of the amount of apparent adsorbed carbon dioxide showed maximum values and the maximum decreased with increasing temperature. The pressures at which the adsorbed amount showed the maximum increased with increasing temperature. The amount of true adsorption evaluated using adsorbed phase density, which was estimated by using the Dubinin-Nikolaev equation, exhibited a general trend whereby the loadings increased with increasing pressure and decreased with increasing temperature. Correlated values of both apparent and true loadings by the Dubinin-Astakhov equation were in good agreement with the exprerimental data.
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Katsuyasu Sugawara, Tomomichi Gun-ji, Takuo Sugawara
1996 Volume 22 Issue 2 Pages
392-395
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The uptake behavior of hydrogen sulfide was observed for a rapid pyrolysis char in a H
2S/N
2 gas stream. More than 13 wt% was obtained for sulfur content in the char contacted with H
2S/N
2 mixture at 1073 K. Chemical analysis indicated that the increment of sulfur attained was organic sulfur solely in solid phase. Gasification was conducted in a carbon dioxide stream at 1073 K for the char which had trapped hydrogen sulfide. The extent of sulfur reduction in the solid phase was smaller than the weight loss of char during gasification to the extent of 44-55%.
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Hiroshi Tachibana, Yasuo Hirose
1996 Volume 22 Issue 2 Pages
396-399
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Many distillation calculation methods at the steady state incorporaing various kind of point efficiencies have been developed for obtaining the actual distillation column composition profile, but a calculation method at the unsteady state incorporating the point efficiency for calculating the time dependence of the column profile from start-up to the steady state has not yet been reported. Here, a method to introduce point efficiencies into the unsteady state distillation calculation is proposed. The principle is as follows : the vapor compositions are eliminated from the derivatives by using the definition equation of point efficiency, so that numerical integration can be carried out with a function of only the liquid compositions. The efficiencies tested are the Murphree vapor, the Murphree liquid and the Hausen efficiencies. Generally speaking, the time required to reach the steady state increases with efficiency increasing. This method is also applicable to the Relaxation method.
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Yuji Kiguchi, Hidetoshi Sekiguchi, Takayuki Watanabe, Atsushi Kanzawa
1996 Volume 22 Issue 2 Pages
400-403
Published: March 10, 1996
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The heat transfer in an endothermic
tert-butanol dehydration reaction was investigated under the condition that the temperature difference between the heat source and the heating medium was extremely small. The conversion per unit volume of catalyst is dependent on the residence time of heating medium, both in a fluidized catalyst bed and in a fixed catalyst bed. The heat flow has a maximum with the mass flow rate of heating medium. The heat flow by this reaction per unit mass flow rate of heating medium is related to the conversion.
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Kazunari Takahashi, Hiroshi Ueda, Eiji Suzuki
1996 Volume 22 Issue 2 Pages
404-407
Published: March 10, 1996
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In the perfusion culture of mammalian cells, the temperature
Tv that maximized the viable cell density at steady state was lower by 6-8°C conpared to temperature
Tg that maximized cell growth rate. The cell density was 2.4 times as high at
Tv as at
Tg. Since the death rate decreased as the temperature was lowered, the difference between the growth and death rates could be large enough to maximize the viable cell density, the difference integrated with culture time. Protein production rate per cell as well as per culture volume was maximized at a temperature several degree higher than
Tv.
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Tomoko Mineo, Masahiko Aihara, Atsushi Tsutsumi, Kunio Yoshida
1996 Volume 22 Issue 2 Pages
408-411
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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A novel technique to produce monodispersed fine particles, named the Three-Phase Alkoxide Method, is proposed, where water vapor is introduced into metal alkoxide alcoholic solutions and hydrolysis of metal alkoxide takes place in a three-phase slurry reactor.
Growth of monodispersed TiO
2 seed particles was studied in a three-phase reactor of titaniumtetraisoproxide (TTIP) ethanol solution by further addition of water vapor.
It was found that uniform particle growth can be controlled over a range of 0. 76 -0.95 μm without agglomeration by changing the amount of water supplied.
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Shigeo Chiba, Yasushi Ohyama, Kazuyuki Harima, Kazuo Kondo, Kunio Shin ...
1996 Volume 22 Issue 2 Pages
412-415
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Agglomerates of 100250 μm consisting of Si
3N
4 primary particles of 0.76 μm were made with a rotary vibrating sieve. Si
3N
4 fine particles were coated with AlN by gas phase reaction with AlCl
3 and NH
3 in some fluidized beds of the agglomerates. The cross sectional distribution of AlN in the agglomerate was measured by EPMA analysis. As a result, uniform deposition of AlN was obtained at a relatively low reaction temperature and low gas velocity.
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Yoshio Fuchigami, Toshiaki Inami, Yosokichi Kobayashi, [in Japanese]
1996 Volume 22 Issue 2 Pages
416-419
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The χ-parameter in the Flory-Huggins equation of methyl methacrylate and polymethyl methacrylate was determined to be χ=0.33, from the observation of vapour pressure of the reaction mixture in a pilot scale reactor for continuous bulk polymerization of methyl methacrylate. The monomer content of the polymer solution flushed from the pressurized heat exchanger to the vent extruder almost agreed with the equilibrium concentration calculated from the Flory-Huggins equation. The monomer content of the resulting pellet (0.150.37%) was far from the equilibrium concentration (0.02%) at the front vent, suggesting that the monomer content must be decreased by improvement of the screw design.
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Kiyoshi Matsuyama, Kenji Mishima, Masanobu Kutsumi, Naoki Komorita, At ...
1996 Volume 22 Issue 2 Pages
420-423
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Vapor-liquid equilibria of aqueous ethanol solutions containing a very small amount of isobutyl acetate and ethyl caprylate were determined using an Othmer-type still at 66.7 kPa. The equilibrium ratio of the minor components increases with decreasing mole fraction of ethanol in the solutions. The results were correlated with the NRTL and UNIFAC equations.
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Yoshihito Kato, Setsuro Hiraoka, Yutaka Tada, Takafumi Ue, Seung-Tae K ...
1996 Volume 22 Issue 2 Pages
424-427
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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The flow patterns in shaking vessels with various geometries were visualized with a tracer method using aluminum powder. The spherical and conical vessels were effective for the shake mixing in the same manner as the cylindrical vessel, because these vessels have circular cross sections that develop the rotational flow. Neither a rectangular vessel, nor a cylindrical vessel with baffles should be used for shake mixing, because rotational flows are not developed in these vessels.
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Mitsuhiro Ito
1996 Volume 22 Issue 2 Pages
428-431
Published: March 10, 1996
Released on J-STAGE: November 12, 2009
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Using a comminution kinetics equation and a classification efficiency equation, a simulation of closed- circuit grinding was carried out under the condition that the fineness is expressed by the sieving mass ratio.
The higher the efficiency of classification, the more the production rate increases. Also, the powder passing rate through the mill, which is indicative of the maximum production rate, shifts to a higher value as classification efficiency increases. The parameters
k and
n have a specific relation under the usual condition of cement grinding. In this condition, the production rate increases with a decrease in the parameter
n under 20-30 μm of the over size ratio 19 % particle diameter. But it increases with an increase in the parameter
n over the diameter.
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1996 Volume 22 Issue 2 Pages
e1a
Published: 1996
Released on J-STAGE: November 12, 2009
JOURNAL
FREE ACCESS
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1996 Volume 22 Issue 2 Pages
e1b
Published: 1996
Released on J-STAGE: November 12, 2009
JOURNAL
FREE ACCESS
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1996 Volume 22 Issue 2 Pages
e1c
Published: 1996
Released on J-STAGE: November 22, 2010
JOURNAL
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